Types of Data: An Introduction

There are two types of data i.e. the primary and the secondary sources of data. These are

briefly stated below as a brief introduction of the two types:

Primary Data: Data collected by investigator for his own purpose, for the first

time, from beginning to end, are called primary data. These are collected from the

source of origin. In other words data originally collected in the process of

investigation are known as primary data. Primary data are original. The concerned

investigator is the first person who collects this information. The primary data is

thus first hand information.

Secondary Data: Secondary data is the information which is already in

existence, and which has been collected, for some other purpose than the

answering of the question at hand. In other words data collected by other persons

is called secondary data. There data are, therefore, called second hand data. These

are available in published or unpublished forms.

Primary Data

Primary sources are sources produced by those who were participants, observers, or in

other respects close to the events and changes they depict.1 Also the data are original

observations collected by the researcher or his agents for the first time for any

investigation and used by them in the statistical analysis.2 Primary data is useful for

current as well as future studies. Primary resources are original sources of information on

which other research is based, including documents such as poems, diaries, court records,

interviews, surveys, and fieldwork. Primary materials also include research results

1 Webster, C.W. John. Studying History. Macmillan India Private Limited. New Delhi. 1997. p. 69.2 Gupta, Santosh. Research Methodology & Statistical Techniques. Deep & Deep Publications Private Limited. New Delhi. 2005. p. 128.

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generated by experiments, which are published as journal articles in some fields of study

and sets of data, such as census statistics which have been tabulated, but not interpreted.3

Hence, it should be collected with utmost care.4 The primary data can be collected

various methods the most popular being the following methods:

Observation Method: In the observation method, the investigator will collect

data through personal observations. Generally, observation method of data

collection deals with the recording of the behavior of respondents/sampling units.

Take the case of consumers transacting with a bank. Here, the behavior of the

consumers like, patience while waiting, way of moving with the bank employees,

helping fellow consumers fill up the forms, etc., will be observed by the

investigator. The identity of the investigator should not be revealed to the

consumers. If it is known to the consumers, they may change their behavior. This

method helps capture the behavior of consumers directly. Bu, it is a time

consuming and costly exercise. Also, it suffers from personal biases of

investigators which will distort the findings.5

Personal Interview: Under this method, data is collected by the investigator

personally by asking questions pertaining to the inquiry from persons from whom

the information is to be obtained. Thus, is a person wants to study the spending

habits of university students he may contact and interview students personally and

collect the desired information. As the investigator is present on the spot for

conducting the enquiry, the data collected by him would be first hand and original

in character.6 The merits of this method are originality of the data, accuracy of the

data, reliability and elasticity of extraction of information from the informant. The

demerits being that the method makes it difficult to cover wider areas causing

limited coverage, there may be presence of personal bias of the inquirer and the

method is expensive.

Indirect Personal Interview: Indirect personal interview is the method by

which information is obtained not from the persons regarding whom the 3 http://library.uwsp.edu/guides/webtutorials/primary.htm4 Panneerselvam, R. Research Methodology. Prentice Hall of India Private Limited. New Delhi. 2008. p.18.5 Panneerselvam, R. Research Methodology. Prentice Hall of India Private Limited. New Delhi. 2008. p.18.6 Gupta, Santosh. Research Methodology & Statistical Techniques. Deep & Deep Publications Private Limited. New Delhi. 2005. p. 135.

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information is needed. It is collected from the other persons who are expected to

possess the necessary information. These persons are known as witness. For

example, by this method, the data on the economic conditions of the workers may

be collected from their employers rather then the workers themselves.7 The merits

of this method are that it helps in covering a wider area while remaining cheaper

and simple. The demerits of this method being that the information is less

accurate, may be biased and may also sometimes lead to doubtful conclusions.

Telephone Interview: Telephone interview is considered to be a cost effective

and dominant data collection method because that travel time of interviews is

totally eliminated, the cost of travel of interviews is also eliminated, there is a

grater possibility of reaching the consumers all over the area, the total time of

conducting the interview of the sample is least when compared to other methods

and there is a grater possibility of random selection of respondents among the

population having a telephone connection. Though it has many advantages the

method has certain disadvantages as well like it is impossible to use visual aids, it

implies exclusion of population who are not having a telephone connection and

the interviewee may discontinue conversation in the midway.8

Mail Survey/ Mailed Questionnaire: Under the mailing method the

questionnaires are mailed to the informants. A letter is attached with the

questionnaire giving the purpose of enquiry. It is also assured that the information

would be kept a secret. The informant notes the answers against the questions and

returns the completed questionnaire to the investigator9. The main advantages of

this method being that this method is economical and helps cover a wider area.

The demerits being that there may be lack of interest on the part of the informant,

there is less flexibility as the informant might not understand what the question

demands exactly, the results are less accurate and subject to bias of the informant.

Questionnaires In-charge of Enumerators: Enumerators are those persons

who help the investigators in collecting the data. Under this method, a 7 Jain, T.R. & Ohri V.K. Statistics for Economics and Indian Economic Development. V.K. Publications. New Delhi. 2009. p.26.8 Panneerselvam, R. Research Methodology. Prentice Hall of India Private Limited. New Delhi. 2008. p.20.9 Jain, T.R. & Ohri V.K. Statistics for Economics and Indian Economic Development. V.K. Publications. New Delhi. 2009. p.29.

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questionnaire is prepared according to the purpose of enquiry. The enumerator

himself approaches the informant with the questionnaire. The questionnaires

which are filled by the enumerator themselves by putting questions are called

schedules. Thus, under this method, the enumerator himself fills the questionnaire

after seeking the information from the informants. The enumerators are given

training to fill the schedules and put the question intelligently to obtain accurate

information10. The merits of this method being that it helps in covering a wider

area with accuracy and completeness. While its shortcomings being that this

method is expensive, time consuming and may be subject to untrained

enumerators or those who may be partial.

Secondary Data

Secondary data is data collected by someone other than the user. Common sources of

secondary data for social science include censuses, surveys, and organizational records11.

Secondary data analysis saves time that would otherwise be spent collecting data and,

particularly in the case of quantitative data, provides larger and higher-quality databases

than would be unfeasible for any individual researcher to collect on their own. In addition

to that, analysts of social and economic change consider secondary data essential, since it

is impossible to conduct a new survey that can adequately capture past change and/or

developments.12 Secondary sources are based on primary sources and produce second-

hand or sometimes even third-hand evidence.13 In other words, secondary data are

collected by others and used by others.14 Secondary resources describe or analyze the

primary sources.15 This type of data is mainly derived from books, publications, foreign

10 Jain, T.R. & Ohri V.K. Statistics for Economics and Indian Economic Development. V.K. Publications. New Delhi. 2009. p.30.11 http://en.wikipedia.org/wiki/Secondary_data 12 http://en.wikipedia.org/wiki/Secondary_data 13 Webster, C.W. John. Studying History. Macmillan India Private Limited. New Delhi. 1997.14 Gupta, Santosh. Research Methodology & Statistical Techniques. Deep & Deep Publications Private Limited. New Delhi. 2005.15 http://library.uwsp.edu/guides/webtutorials/primary.htm

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government publications, international bodies’ publications, technical or trade reports,

association reports, public reports, etc.

The chief sources of secondary data can be classified according to 2 methods. The

first method differentiates according to whether the source is published or unpublished.16

While the second basis differentiates on the grounds of internal and external sources.17

According to the first mode of differentiation the sources are divided as under:

Published Sources: There are a number of national organizations and

international agencies which collect data relating to the various spheres like

business, labor, production, etc., to name a few. This data is periodically

published and serve as a very important source of secondary data. The various

sources are listed below:

o Official Publications of Central Government

o Publications of Semi-Government Statistical Organizations

o Publications of Research Institutions

o Publications of Commercial and Financial Institutions

o Reports of Various Committees and Commissions Appointed by the

Government

o Newspapers and Periodicals

o International Publications

Unpublished Sources: These sources include things like personal diaries,

letters, memoirs, biographies, etc.

As per the second method do division sources are of the following types:

Internal Sources: Internal sources of secondary data for marketing

applications are as follows:

o Sales records

16 Gupta, Santosh. Research Methodology & Statistical Techniques. Deep & Deep Publications Private Limited. New Delhi. 2005.17 Panneerselvam, R. Research Methodology. Prentice Hall of India Private Limited. New Delhi. 2008.

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o Market activity

o Cost information

o Distributor reports and feedback

o Consumer feedback

External Sources: Various external sources of data are government

publications, government publications, journals, publications of trade

associations, books, magazines, newspapers, annual reports, etc. This form

even includes publications from the UN, WHO, ILO, etc.

Principal Differences between Primary & Secondary Data

“The distinction between primary and secondary data is one of the degree. Data which

are primary in the hands of one party may be secondary in the hands of the other.”

-Secrist18

The following are some principal differences between primary and secondary data:

Difference in Originality: Primary data are original because they are collected

by the investigator from the source of their origin. Against this, secondary data

are already in existence and, therefore, are not original.19

Difference in the Suitability of Objectives: Primary data are always related

to a specific objective of the investigator. These data, therefore, do not need any

adjustment for the concerned study. On the other hand, secondary data have

already been collected for some other purpose. Therefore, these data need to be

adjusted to suit the objective on the study in hand.20

18 Jain, T.R. & Ohri V.K. Statistics for Economics and Indian Economic Development. V.K. Publications. New Delhi. 2009. p.24.19 Jain, T.R. & Ohri V.K. Statistics for Economics and Indian Economic Development. V.K. Publications. New Delhi. 2009. p.23.20 Ibid.

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Difference in Cost of Collection: Primary data are costlier in terms of time,

money and efforts involved than the secondary data. This is because primary data

are collected for the first time from their source of origin. Secondary data are

simple collected from the published or unpublished reports. Accordingly, they are

much less expensive.21

Choice between Primary and Secondary Data

The choice between primary and secondary sources of data mainly depends upon

the nature, objectives and scope of inquiry availability of time and money, degree of

accuracy desired and the status of the investigator. The primary data are more reliable on

the face, but the secondary data can be relied only be examining the source from which

they have been obtained, their true significance, incompleteness and method of

collection. Sometimes in a certain investigation both primary and secondary data are used

as supplement to each other, it may be pointed out that today in a large number of

statistical inquiries secondary data are generally used because fairly reliable published

data on a large number of diverse fields are now available. In face, primary data are

collected only if there do not exist any secondary data suited to the investigation under

study. The points discussed as under are noteworthy for the preference of primary source

in comparison to the secondary source22:

The primary source gives data in grater details compared to secondary source.

The Secondary source often omits part of the information.

In the secondary source, there is a possibility of mistakes due to errors in

transcription made then the figures were copied from primary source.

21 Jain, T.R. & Ohri V.K. Statistics for Economics and Indian Economic Development. V.K. Publications. New Delhi. 2009. p.24.22 Gupta, Santosh. Research Methodology & Statistical Techniques. Deep & Deep Publications Private Limited. New Delhi. 2005. p. 129

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The primary source includes definitions of terms and units used. It is essential that

the investigations understand the meaning of units in which data are recorded.

The primary source also includes a copy of the schedule used in data collection

together with the prescription of the procedure used in selecting the sample and the size

of the sample.

The availability of time at the disposal of investigations also affects the choice of

method to be adopted in the collection of data. If the data is needed immediately then

secondary sources are taken. On the other hand, if time is sufficient, it is recommended to

use primary method of data collection because primary data are more accurate and

reliable compared to secondary data.

The availability of finance also influences the method to be adopted in the

collection of data. If the data collecting authority has vast financial resources at its

disposal, it is better to adopt primary method. On the contrary, if the data collecting

agency has less financial resources, secondary data should be adopted even though the

secondary data is are not as reliable as primary data.

The availability of trained investigators also affects the choice of the method to be

employed in data collection. If trained investigators are available, primary method should

adopted for the collection of data. In case of non-availability of trained investigators, it is

recommended to adopt secondary method of data collection.

The objective and the scope of the enquiry also determine the method to be

adopted in the collection of data. The selected method must suit the objective and the

scope of the inquiry.

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Problems to be kept in Mind While Using Data

While using either of primary or secondary data problems to be kept in mind to avoid

future difficulties are as under:

The Problem of Genuineness Main aim is to get evidence and this has to be the closest to the truth i.e. objective to

problem of genuineness arises. For example if a source entitled ‘The Presidential Address

of Jawaharlal Nehru delivered at the Indian National Congress at Lahore, December 29,

1929’ is in fact an exact copy of Nehru’s own Presidential remarks on that occasion then

the source is genuine.23 The second possibility is that the source is a forgery, or partly

forged or written by an anonymous writer for Nehru.

The Problem of ReliabilityA document may be one hundred percent genuine and still contain large quantities of

misinformation. One should therefore cross-examine each source in order to determine

the degree of reliability or trustworthiness of the evidence contained in it.24 One should

consider various questions while checking the reliability of the like what was the position

of the facts in consideration? Is the examiner a trustworthy person? What are the sources

used to collect the data? Was a proper method used to collect the data? Was the time of

data collection appropriate to the study?

The Problem of Suitability of DataThe kind of data that may be useful to one study might not be suitable for the other study.

One has to scrutinize the data to ascertain its suitability in the study being conducted. It is

necessary to keep in mind the object, scope and nature of the inquiry being made.

23 Webster, C.W. John. Studying History. Macmillan India Private Limited. New Delhi. 1997. p. 73.24 Webster, C.W. John. Studying History. Macmillan India Private Limited. New Delhi. 1997. p. 77.

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The Problem of Adequacy of DataThe data being used to construct the inquiry must also be adequate for the study being

made. For example data is considered inadequate if it’s related to a narrower area or a

wider area than the area under question. It is found that the data are suitable for the

purpose of the investigation; they should be tested for adequacy. Adequacy of the data is

to be judged in the light of the requirements of the survey and the geographical area

covered by the available data.

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Bibliography

Gupta, Santosh. Research Methodology & Statistical Techniques. Deep &

Deep Publications Private Limited. New Delhi. 2005.

Kothari, C.N. Research Methodology: Methods & Techniques. New Age

International Publishers. New Delhi. 2008.

Panneerselvam, R. Research Methodology. Prentice Hall of India Private

Limited. New Delhi. 2008.

Webster, C.B. John. Studying History. Macmillan India Private Limited. New

Delhi. 1997.

Jain, T.R. & Ohri, V.K. Statistics for Economics and Indian Economic

Development. V.K. Publications. 8th Edition. New Delhi. 2009.

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Webography

http://library.uwsp.edu/guides/webtutorials/primary.htm

http://www.collectionscanada.gc.ca/education/008-3010-e.html

http://library.ucsc.edu/help/howto/distinguish-between-primary-and-secondary-

sources

http://www.collectionscanada.gc.ca/education/008-3010-e.html

http://www.wwnorton.com/college/history/ralph/research/prisec.htm#primary 

http://www.lib.berkeley.edu/TeachingLib/Guides/PrimarySources.html

http://en.wikipedia.org/

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